Tamper-proof screw cap

ABSTRACT

A screw closure of plastic comprising a head plate (2) and a cylindrical cap skirt (3) which extends downwardly from the head plate and has a female thread (4), and a tamper-evident band (5) connected to the lower edge of the cap skirt (3) and provided with radially inwardly projecting retaining elements (6) which define a smallest inside diameter of the tamper-evident band (5) in such a way that they can engage behind a retaining ring (25) of larger diameter on a container neck (20) in order to remain on the container neck (20) after separation from the cap skirt (2), characterised in that extending between the lower edge of the cap skirt (2) and the tamper-evident band (5) is a peripherally extending tear-off band (7) which is connected by way of a respective tear line (8, 8′) on the one hand to the cap skirt (2) and on the other hand to the tamper-evident band (5).

The present invention concerns a screw closure of plastic comprising ahead plate and a cylindrical cap skirt which extends downwardly from thehead plate and has a female thread, and a tamper-evident band connectedin one piece to the lower edge of the cap skirt and provided withradially inwardly projecting retaining elements which define a smallestinside diameter of the tamper-evident band in such a way that they canengage behind a retaining ring of larger diameter on a container neck inorder to remain on the container neck after separation from the capskirt—if wanted—.

Container closures of plastic of that kind have been standard for manyyears. When the closure is opened a connection between the lower edge ofthe cap skirt and the tamper-evident band is torn as the tamper-evidentband engages with its radially inwardly projecting retaining elementsbehind a retaining ring of larger diameter that is arranged on acontainer neck and consequently cannot follow the axial movement of theclosure which in other respects comprises the head plate and the capskirt, when the screw closure is unscrewed.

The tear line between the tamper-evident band and the lower edge of thecap skirt can be of various different configurations. For example it mayinvolve a portion in the cap skirt and the tamper-evident band, which isintentionally produced in the form of a thin-wall part. Frequentlyhowever the connection between the cap skirt and the tamper-evident bandis completely separated along larger portions of the periphery, in whichcase the length of those portions is limited by narrow, easily tearablebridges which interrupt the peripherally extending separation line.

In that arrangement the connection between the cap skirt and thetamper-evident band, which is correspondingly weak along a tear line, isalso relatively easy to tear for the reason that, when the screw closureis unscrewed, the thread effectively provides a transmission ratiosimilarly to a worm transmission as the thread configuration isrelatively shallow and the torque acting in the peripheral direction isconverted into a comparatively high axial force between the cap skirtand the tamper-evident band. In addition by virtue of the frictionalforces between the container neck and the tamper-evident band and therelative rotation caused thereby of the cap skirt with respect to thetamper-evident band shearing forces occur, which make it easier for thecap to be torn off the tamper-evident band.

It has been found however that the conventional screw closures withtamper-evident band, in spite of numerous measures which have also beenimplemented on corresponding bottle necks, in order for example toprevent the tamper-evident band from being levered off without tearingthe connection to the cap skirt, are still not sufficient to excludemanipulation operations. Particularly in the case of containers having arelatively costly content, for example in the agricultural and chemicalsector but also in the case of expensive spirits, it seems that in manycountries the contents of the containers make it worth incurringrelatively great cost and effort to apparently restore a closure whichhas already been opened and to apply it to a container with counterfeitcontents.

In that case for example torn bridges between the tamper-evident bandand the cap skirt are restored by adhesive means or the tamper-evidentband is glued back on along the entire periphery to simulate an intacttear line. Experience shows that in some cases of forgers screw closuresare used which look entirely similar and are produced using the simplesttools in an injection moulding process in relatively small quantities ofa few thousand, possibly removed from a mould by hand and screwed byhand on to cleaned empty bottles of a brand owner after filling withcounterfeit content. A consumer who is not quite particularly payingattention and taking care cannot see the difference in relation tooriginal closures on a store shelf.

DE 10 2006 001 323 discloses a snap closure which does not have ascrewthread but is only latched on the container neck by axial pressureand which substantially comprises a closure cap having a snap edge and aholding ring which are pivotably connected together by way of a hingeportion. The holding ring of a relatively smaller diameter engagesbehind an annular enlargement of relatively larger diameter on thecontainer neck and thus durably fixes the closure on the container neck.The closure is selectively moved into the closed or the open position bypivotal movement of the closure cap with respect to the holding ring.

A connection between a holding ring and a closure cap similarly to thetear line between a cap skirt and a tamper-evident band in the case of ascrew closure is not appropriate in that case because an averageconsumer would not be in a position to tear that connection simply bylifting the closure cap. For that reason provided on the snap closure inaccordance with DE 10 2006 001 323 between the closure cap and theholding ring is a tear-off band which is connected by way of twoparallel tear lines on the one hand to the closure cap and on the otherhand to the holding ring and which is torn away radially outwardly bymeans of a gripping tab prior to opening the closure cap and thusseparates the connection between the holding ring and the closure capoutside the hinge portion.

In snap closures therefore the provision of tear lines by a tear-offband which is to be pulled off radially is predominantly effected forthe reason that tear lines can be separated more easily by shearingforces transversely relative to the axial direction of the closure, thansolely by lifting off the cap. For a screw closure which shears theconnection off along a tear line by rotation of the screw cap and/orwhich axially tears away to an increased degree by virtue of the threadtransmission ratio such a tear-off band arranged between the cap skirtand the holding ring and provides an indirect connection between the capskirt and the holding band seems to be unnecessarily complicated.

Such a tear-off band therefore indirectly forms a connection between thecap skirt and the holding band, but is previously not known in relationto screw closures, as in the case of screw closures there is not acorresponding necessity to reduce the force required for separating thetamper-evident band from the cap skirt by the provision of a tear-offband.

A conventional plastic screw closure with tamper-evident band isconsidered as the most relevant state of the art.

In comparison with that state of the art the object of the presentinvention is to provide a screw closure having the features set forth inthe opening part of this specification, which as far as possibleexcludes the above-described manipulation actions and which canguarantee even greater security for the container contents.

That object is attained in that extending between the lower end portionof the screw closure, that is in the form of a holding andtamper-evident band, and the upper part which is in the form of thescrew cap, is a peripherally extending tear-off band which is connectedby way of a respective tear line on the one hand to the cap skirt and onthe other hand to the tamper-evident band/holding band, wherein thetear-off band is of such a design and is so connected to the cap skirtand/or the tamper-evident band that it is deformed irreversibly as muchas possible upon being torn off.

The closure according to the invention therefore comprises threesubstantially cylindrical or annular elements which are integrallyconnected together, namely a screw cap which in turn comprises a headplate and a cap skirt with a female thread, the tear-off band and thetamper-evident band.

The screw closure according to the present invention accordingly hasbetween the cap skirt and the tamper-evident band a completelyperipherally extending tear-off band which exclusively by way of twotear lines makes the connection between the cap skirt and thetamper-evident band and which can thus be completely separated at leasteither from the tamper-evident band or from the cap skirt or from bothand thus after being torn off leaves behind a clearly visible andnon-closable gap between the tamper-evident band and the cap skirt.

The tear-off band therefore has an essential part to play in thetamper-evident function of the screw closure insofar as its presence orabsence between the lower part of the screw closure, referred to as the‘tamper-evident band’, and the lower edge of the cap skirt, is veryclearly perceptible and in particular even more clearly perceptible thanthe gap between the tamper-evident band and the cap skirt, that in thecase of conventional screw closures is produced after a tamper-evidentband directly connected to the lower edge of the cap skirt has been tornoff but that can also be closed again by displacement of thetamper-evident band which has been separated from the screw cap.

In contrast to the last-mentioned case in the state of the art the gapbetween the cap skirt and the tamper-evident band in the closureaccording to the invention is no longer to be readily closed bydisplacement of the tamper-evident band and glueing to the lower edge ofthe cap skirt as, with the usual and mutually matched dimensions of thescrew closure and the container neck, the retaining ring for thetamper-evident band on the container neck holds the tamper-evident bandat a spacing relative to the cap skirt.

Accordingly the tear-off band is connected both to the lower edge of thecap skirt and also to the upper edge of the tamper-evident band by wayof a respective tear line, wherein the tear-off band at a suitableperipheral position (at one end of the tear-off band) has a grippingtab, by way of which the tear-off band can be entirely or partially tornopen along both tear lines by a radially outwardly acting pulling forceand, if desired, can be separated from the closure cap skirt. In thiscase there is no need for any excessively high forces as the tear-offband is not closed in the peripheral direction but has a free end whichis connected to the gripping tab. When the tear-off band is radiallypulled off the cap a shearing force can be exerted on the tear lines byway of the tab, more specifically only ever point-wise at the transitionbetween a portion of the tear-off band which has already been detached,to a portion which is still connected, so that the materialprogressively tears along the tear line until finally the entiretear-off band can be removed or however also remains connected to one ofthe parts of the tamper-evident band or screw cap, by way of a residualsegment of the periphery. The force to be applied in that case isrelatively slight and is markedly less than would be required whenaxially stretching and tearing through the tear lines at the same timealong the entire periphery.

The tear-off band which is no longer required in most cases after beingtorn off and is disposed of by the consumer as waste also makes itsubstantially more difficult for a fraudster after complete removal ofthe tear-off band, to restore a closure to the apparently original stateagain.

In contrast thereto in the case of a conventional screw closure allparts of the closure remain on the bottle neck even after opening.

That measure of separating off the tear-off band and disposing of itseparately from the other parts of the closure, considered in itself,could still not prevent a fraudster already gathering up again andfitting together at the point of sale—for example a filling station—allthree parts of the closure. In that case in a similar fashion to thesituation involving the above-described manipulation operations, itwould also be possible for two intact tear lines, namely that betweenthe tear-off band and the cap skirt and that between the tear-off bandand the tamper-evident band, to be restored by being glued together to astate which simulates the original condition for a consumer who is onlysuperficially checking.

According to the invention however that is prevented in that thetear-off band is of such a configuration and is so connected to the capskirt and/or the tamper-evident band that it is irreversibly deformedupon being torn off. The irreversible deformation can then no longer bereversed so that even upon the attempt to restore the connection betweenthe tear-off band and the cap skirt and the tamper-evident band, thedeformation of the tear-off band gives a clear indication that theclosure has already been opened once and is no longer in its originalstate.

Therefore, for example to avoid waste, the tear-off band cannot becompletely separated from one of the parts of the closure and forexample can still remain connected to a portion of the tamper-evidentband. Nonetheless however the originally one-part screw closure isdismembered in such a way and in particular the tear-off band isdeformed in such a way that it is not possible for the parts to bere-assembled without that being easily visible.

Irreversible deformation of the tear-off band can be achieved inter aliaby the tear-off band along its periphery comprising alternatelyrelatively more easily and relatively less easily stretchable portions.During the tearing-off operation the less easily stretchable portionsthen resist the forces occurring on tearing off the band and the moreeasily stretchable portions are stretched more greatly. Stretchabilityat least of the easily stretchable portions is self-evidently matched tothe tearing strength of the tear line so that the force required fortearing the tear lines at any event also causes stretching of the moreeasily stretchable portions.

The reversible deformation can also be promoted inter alia if one orboth tear lines are somewhat more resistant in the region of the lesseasily stretchable portions than in the region of the easily stretchableportions, which further increases the difference in stretch. That isachieved for example by different cross-sections for the connectingpoints between easily tearable bridges between the tear-off band and thecap skirt and the tamper-evident band respectively or by a fluctuatingwall thickness of a peripherally extending weakening line.

A further feature of an embodiment of a closure according to theinvention provides that the tear-off band and/or the tamper-evident bandon the inside thereof have a tooth arrangement which upon engagementwith a corresponding tooth arrangement on a container neck preventsrotation of the tear-off band or tamper-evident band together with thescrew cap of the closure in the opening direction. The tooth arrangementmakes it difficult to open the closure solely by rotating the screw capbecause a multiplicity of teeth are simultaneously in engagement androtation of the screw cap would require tearing of the tear line at thesame time along its entire periphery. The tooth arrangement between thetear-off band and the container neck therefore forces the consumerfirstly to tear off the tear-off band and dispose of it.

The individual teeth in the region of the tear-off band and thetamper-evident band, in particular the teeth on the inside of thetamper-evident band and the tear-off band, can involve the same or alsodifferent peripheral angle spacings. Preferably to open the screwclosure the consumer should be more or less compelled firstly to removethe tear-off band before the screw cap can be turned in the openingdirection. Preferably the tear-off band is interrupted along itsperipheral direction in the peripheral direction so that, after completeopening of the closure, it is completely released from the containerneck and in addition is already irreversibly deformed previously duringseparation along the tear lines.

The tear line can be provided in different ways, for example by shapinga tear line or by a peripherally extending interruption with axial limbsin an injection moulding process or also, after injection moulding ofthe closure, as a unit with the tear-off band and the tamper-evidentband, by cutting into the connecting region between the tear-off bandand the cap skirt and the tamper-evident band, wherein the connectionbetween the tear-off band and the adjacent elements can also becompletely separated along individual peripheral portions so that onlyindividual, easily tearable limbs remain. A peripherally formed incisionalong a tear line can also be implemented at different peripheralpositions to differing depth in order to provide more easily tearableand less easily tearable portions, which promote irreversibledeformation of the tear-off band.

As already mentioned the tear-off band itself, viewed in the peripheraldirection, can also comprise alternately relatively easily and lesseasily stretchable portions. The alternately relatively more easily andless easily stretchable portions can in particular comprise alternatelyradially thinner and thicker regions of the tear-off band.

The alternately relatively more easily and less easily stretchableportions can further be of a differing width, that is to say varyingfrom one portion to another, as measured in the peripheral direction.

The stretchability of the tear-off band can also vary in the axialdirection and that variation in stretchability, in particular by virtueof differing wall thicknesss of the tear-off band, can also be limitedto one or more peripheral portions which in turn can involve differingstretching in the peripheral direction. For example regions of differingwall thicknesses of the tear-off band can extend along a zig-zag linebetween the tear line towards the tamper-evident band and between thetear line towards the cap skirt along the periphery of the tear-offband.

One of the free ends of the tear-off band can also have a tear-off tabwhich can be gripped from the outside in order, before turning the screwcap to open the closure, to pull off the tear-off band along the entireperiphery in order in that way to permit opening of the closure and tobe able to implement that using substantially less force than would beapplied if the tear lines would have to be separated solely by theturning movement of the screw cap.

The tear lines could preferably also be of a firm configuration so thatopening of the closure without previously releasing the tear-off bandalong the entire periphery would not be possible or would be possibleonly with a very great deal of trouble, scarcely, that is to say solelyby turning the screw cap, while the shearing action due to transverseforces, as is relatively easily possible upon gripping a tear-off taband moving the tab radially away to separate the tear lines, because theforce for separating the tear lines, if it is to be respectively appliedonly in point form in the region of a part of the tear-off band whichhas already been detached to a part which is still connected,progressively along the entire periphery, is substantially less than theforce required in order for example when unscrewing the cap to separatethe tear lines practically simultaneously along the entire periphery. Atany event however the tear-off band is completely separated either fromthe cap skirt or from the tamper-evident band or from both, either byrotation of the screw cap or preferably by previously tearing off thetear-off band.

An embodiment provides that the tear-off band extends along the entireperiphery of the closure, with the exception of an interruption limitedto less than 5° peripheral angle. The tear-off band thus has twodirectly mutually opposite free ends. In that case one of the ends canbe provided with a gripping tab which radially outwardly covers over theother end.

The tear-off band can for example firstly be produced in the form of acompletely peripherally closed tear-off band, together with the screwcap and the tamper-evident band, by injection moulding, wherein afterremoval from the mould the tear-off band is severed by an axial cutshortly before the attachment of the gripping tab.

An additional security measure lies in the printing on the closure cap,which is difficult to counterfeit, in particular with a print image,which extends on the outside of the closure cap over one or both tearlines and thus over the cap skirt, the tear-off band and/or thetamper-evident band.

Such a print image is preferably produced by a laser printer or anothersimilarly costly and complex printing machine which can print curvedsurfaces of 3-dimensional bodies in such a way that forgeries are verydifficult.

To make it easier to unscrew the closure cap the cap skirt can also havean external knurling.

Further advantages, features and possible uses of the present inventionwill be clearly apparent from the description hereinafter of a preferredembodiment and the accompanying Figures in which:

FIG. 1 shows a side view of a closure according to the invention,

FIG. 2 shows a sectional view containing the axis of the closure,

FIG. 3 shows a sectional view of the closure from below along line V-Vin FIG. 2,

FIG. 4 shows a side view of a closure fitted on an associated containerneck,

FIG. 5 shows a sectional view containing the axis of a closure fitted onto a container neck,

FIG. 6 shows a sectional view along line VI-VI in FIG. 4,

FIG. 7 shows the side view of an associated container neck,

FIGS. 8a, b show two sectional views of the tear-off band and theadjoining parts in the sectional planes containing the closure axis atdifferent angular positions, and

FIGS. 9a, b show a side view and a perspective view of a closure withouttear-off band on a container neck.

The external view shown in FIG. 1 illustrates a screw closure 10 havinga screw cap 1 comprising a head plate 2 and a cap skirt 3, which in turnis connected by way of a tear line 8 to a tear-off band 7 connected to atamper-evident band 5 by way of a further tear line 8′. The screwclosure comprises a single plastic part, that is to say the screw cap 1(consisting of cap skirt 3 and head plate 2) is produced in one piecetogether with the tear-off band 7 and the tamper-evident band 5 in aninjection moulding process, wherein the material which hasremained—possibly after further processing—in the region of the tearlines 8, 8′ produces the connection between all three parts.

It is also possible to see at a peripheral position of the tear-off banda gripping tab fitted at a free end of the tear-off band 7 which isinterrupted at that location in the peripheral direction. The grippingtab 13 can possibly also have an easily tearable connection to the otherend of the tear-off band, that is directly opposite the end providedwith the gripping tab. References 7′ and 7″ in FIG. 1 indicate differentportions of the tear-off band which are of differing wall thickness orwhich in part form projections and recesses and thereby when the band istorn off provide that the tear-off band 7 is deformed.

The tear-off band has two directly opposite free ends. It can firstly beproduced for example in the form of a completely peripherally closedtear-off band with the screw cap 1 and the tamper-evident band 5 and canthen be severed by an axial cut shortly before the attachment of thegripping tab 13.

It can be seen from the sectional view in FIG. 2 that the cap skirt 3 ofthe screw cap 1 on its inside has a thread 4 which can be interrupted byventing grooves 4′. In this case the tear line 8 is formed by aperipherally extending separation line which is interrupted only byeasily breakable bridges 12 which hold the tear-off band 7 and the capskirt 3 together. The tear line 8′ is also formed by a peripherallyextending separation line which is also interrupted by easily breakablebridges 12′ between the tear-off band 7 and the holding band 5. When thegripping tab 13 is lifted and moved radially away from the closure theindividual bridges 12′ are gradually torn away and the tear-off band 7is separated from the cap skirt 3 and the tamper-evident band 5 in thatway and can be removed along the periphery of the screw closure 10 sothat thereafter between the cap skirt 3 and the tamper-evident band awide gap separates the cap skirt 3 from the tamper-evident band 5 andthere is no longer any connection between the cap skirt and thetamper-evident band. The tamper-evident band in turn on its inside alsohas a so-called folded-over flexband 6 which prevents displacement orremoval of the tamper-evident band 5 upwardly in the direction of thecap skirt 3.

Unscrewing of the cap without separation of the tear-off band isprevented by teeth 9 on the inside of the tear-off band 7, that comeinto engagement with a corresponding counterpart tooth arrangement 19 ona container neck 20 and prevent rotation of the tear-off band. Theconnection between the tear-off band 7 and the cap skirt 3 by aplurality of easily breakable bridges then prevents the closure cap frombeing released. Otherwise for simultaneously breaking all bridge 12 itwould be necessary to apply a force such as a normal consumer would notapply. The consumer is therefore more or less compelled to remove thetear-off band 7 to be able to open the closure. The easily breakableconnection along the tear lines 8 and 8′ could therefore also becomparatively stronger than the connection between the tamper-evidentband and the cap skirt in conventional screw closures as, when thetear-off band is radially pulled off, the bridges 12, 12′ areindividually successively broken.

In order to open the closure without removal of the tear-off band incontrast all of the easily breakable bridges would have to bepractically simultaneously torn, which would require a correspondinglyhigh force.

FIG. 4 shows the screw closure 10 fitted on a container neck 20 whileFIGS. 5 and 6 show the screw closure 10 fitted on the container neck 20in a section containing the axis of the closure and in a sectionperpendicularly to that axis respectively. It will be seen from FIG. 5that the spacing between the tamper-evident band and the lower cap edgeis initially bridged over by the tear-off band but that spacing is alsonot noticeably reduced after removal of the tear-off band 7 because theretaining ring 25 at the periphery of the container neck only permitsslight axial play of the tamper-evident band 5.

FIG. 7 shows the container neck 20 without the screw closure 10. Aparticularity of this container neck 20 lies in the provision of asuitable counterpart tooth arrangement 19 to the tooth arrangement 9 atthe inside of the tear-off band 7, that prevents rotation of thetear-off band 7 in the opening direction together with the screw cap 1.The retaining ring 25 is disposed beneath the counterpart tootharrangement 19 at a spacing from the upper opening edge of the containerneck, which as usual is slightly less than the internal spacing betweenthe inside of the head plate and the top side of retaining elements onthe tamper-evident band, that come into engagement with the underside ofthe retaining ring, so that the tamper-evident band 5 of the screwclosure 10 has only a slight axial mobility. That is also necessary inthe case of conventional closures to prevent easy access from theexterior to the tamper-evident band that would permit manipulation ofthe screw closure.

FIG. 8 shows two sectional views through the region of a tear-off band 7in section planes respectively containing the axis, but at differentperipheral positions 7′, 7″ of the tear-off band 7. The section in eachcase shows the tear-off band 7 and the two tear lines 8 and 8′respectively, forming the transition on the one hand to the cap skirt 3and on the other hand to the tamper-evident band 5. As will be seen thecross-sections of the tear-off band differ markedly from each other atthe different peripheral positions and also the directly adjoiningportions of the cap skirt 3 and also the tamper-evident band 5 areadapted in respect of their thickness and position to the respectiveconfiguration of the cross-section of the tear-off band 7. The result ofthis is that, on being torn off the closure cap, the tear-off band 7 ismore or less deformed depending on the respective local cross-section,in which respect the adjoining portions of the cap skirt and thetamper-evident band 5 are at least partially affected thereby. Theresult of this is that it is practically impossible for the tear-offband 7 to be subsequently re-inserted into the gap between thetamper-evident band and the cap skirt and there to join it by adhesiveor welding to the cap skirt and the tamper-evident band without thatmanipulation being nonetheless clearly visible.

By virtue of a suitable design in respect of the shape and wallthickness of the tear-off band, that can be varied in many respects,inter alia also by a stepped axial contour, the tooth arrangements 9,the repetition spacing of which, also in relation to the length and thevarying repetition spacing of the different peripheral portions 7′, 7″,different wall thicknesses along the periphery and/or in the axialdirection, different distribution of the teeth 9 and so forth, andfinally also by virtue of the design configuration of the tear lines orthe adjustment of their tearing strength, the tear-off band 7 can besuch that it is markedly visibly and irreversibly deformed by the forcesoccurring when tearing off the tear-off band. It is then practically notpossible to re-position a tear-off band again once it has been torn offon a closure and to connect it to the cap skirt 3 and the tamper-evidentband 5 without that manipulation being clearly recognizable.

FIG. 9 shows a side view (FIG. 9a ) and a perspective view (FIG. 9b ) ofthe closure 10 fitted on a container neck 20 after removal of thetear-off band 7. As will be seen a clear gap opens up between the loweredge of the cap skirt 3 of the screw cap 1 and the upper edge of thetamper-evident band 5, and that gap makes it clearly discernible thatthe tear-off band was removed and thus the closure has evidently alreadybeen opened.

Admittedly the tamper-evident band 5 has a certain axial play on thecontainer neck 20 but even when the screw cap is firmly screwed on andeven when the tamper-evident band 5 is axially pushed up as far aspossible there is always a gap between the lower edge of the cap skirt 3and the upper edge of the tamper-evident band 5, that approximatelycorresponds to the axial width of the tear-off band previously disposedin that region.

1. A screw closure of plastic comprising a head plate (2) and acylindrical cap skirt (3) which extends downwardly from the head plateand has a female thread (4), and a tamper-evident band (5) connected tothe lower edge of the cap skirt (3) and provided with radially inwardlyprojecting retaining elements (6) which define a smallest insidediameter of the tamper-evident band (5) in such a way that they canengage behind a retaining ring (25) of larger diameter on a containerneck (20) in order to remain on the container neck (20) after separationfrom the cap skirt (2), characterised in that extending between thelower edge of the cap skirt (2) and the tamper-evident band (5) is aperipherally extending tear-off band (7) which is connected by way of arespective tear line (8, 8′) on the one hand to the cap skirt (2) and onthe other hand to the tamper-evident band (5).
 2. A screw closureaccording to claim 1 characterised in that the tear-off band (7) has aninternal tooth arrangement (9) which upon engagement with oppositelydirected teeth (19) on a container neck (20) prevents a rotary movementof the tear-off band (7) about the closure axis at least in the openingdirection of the closure (10).
 3. A screw closure according to claim 1characterised in that the tamper-evident band (6) has an internal tootharrangement (11) which upon engagement with oppositely directed teeth(19′) on a container neck (20) prevents a rotary movement of thetamper-evident band (6) about the closure axis in an opening directionof the closure (10).
 4. A screw closure according to claim 1characterised in that the tear line (8, 8′) between the tear-off band(7) and the cap skirt (2) and/or the tamper-evident band (6) is producedby an incision in the plastic material which is initially thicker afterproduction by means of injection moulding along the configuration of thetear line.
 5. A screw closure according to claim 1 characterised in thatthe tear-off band (7) is connected to the cap skirt (2) and/or to thetamper-evident band (6) exclusively by easily breakable bridgesdistributed along the peripherally extending tear line (8, 8′).
 6. Ascrew closure according to claim 1 characterised in that viewed in theperipheral direction, the tear-off band (7) comprises alternatelyrelatively more easily (7″) and less easily stretchable portions (7′).7. A screw closure according to claim 6 characterised in that thealternately relatively more easily and less easily stretchable portions(7′, 7″) comprise alternately radially thinner and thicker regions ofthe tear-off band (7).
 8. A screw closure according to claim 6characterised in that the alternately relatively more easily and lesseasily stretchable portions (7′, 7″) are of a width varying along theperiphery as measured in the peripheral direction.
 9. A screw closureaccording to claim 6 characterised in that the more easily and lesseasily stretchable portions (7′, 7″) as viewed in the peripheraldirection are distributed differently in axially different regions ofthe tear-off band (7).
 10. A screw closure according to claim 1characterised in that the cross-section of the tear-off band (7), asmeasured perpendicularly to the peripheral direction, varies along theperipheral direction.
 11. A screw closure according to claim 1characterised in that the tear-off band (7) comprises various axialportions of differing outside diameter, which are connected together bya conical transitional portion.
 12. A screw closure according to claim 1characterised in that the tear-off band (7) has two ends, of which atleast one end has a gripping tab (13).
 13. A screw closure according toclaim 1 characterised in that the tear-off band (7) extends along theentire periphery of the closure with the exception of an interruptionlimited to less than 5° peripheral angle.
 14. A screw closure accordingto claim 1 characterised in that the gripping tab (13) disposed at afree end of the tear-off band (7) is arranged radially outside the twomutually oppositely disposed free ends of the tear-off band (7) andcovers said ends outwardly.
 15. A screw closure according to claim 1characterised in that the cap skirt (3) has an outer gripping knurling.16. A screw closure according to claim 1 with external printing, whichextends on the outside of the closure cap (1) over one or both tearlines (8, 8′).
 17. A screw closure according to claim 19 characterisedin that the print image on the cylindrical outside surface of the screwclosure (1) is so designed that it is to be produced only with a complexprinting process.
 18. A screw closure according to claim 16 withexternal printing which extends on the outside of the closure cap (1)over one or both tear lines (8, 8′) and over the cap skirt (3), thetear-off band (7) and/or the tamper-evident band (5).
 19. A screwclosure according to claim 16 wherein the external printing is a printimage.
 20. A screw closure according to claim 17 where the complexprinting process is laser printing.